A design structure for electrostatic protection of broken code display screen

Abstract

The present invention discloses a design structure for electrostatic protection of a broken code display screen, including a conductive film of an upper ITO glass, an anti-static shielding wiring, an FPC wiring, a discharge TVS tube, a silver paste point and a conductive Mylar. The upper ITO glass is a double-sided conductive ITO glass, the top surface of the upper ITO glass is covered with a layer of ITO conductive film, the upper surface of the upper ITO glass is designed with a common electrode COM-ITO wiring, the surface of the lower ITO glass is designed with a pen segment SEG-ITO wiring corresponding to a working pattern, the lower surface of the upper ITO glass is one-to-one corresponding to the pattern of the upper surface of the lower ITO glass, the surface of the lower ITO glass is an ITO pattern wiring, and a layer of the ITO conductive film is adhered to the upper surface of the ITO glass. The present invention utilizes shielding grounding to maintain a synchronous signal with the driving wiring on the surface, without phase difference, the working display pattern has no potential difference, and the electric field cannot be self-built, so the liquid crystal molecules cannot be deflected; when static electricity is generated on the ITO film, the static electricity charge can be quickly drained, and there will be no residual charge on the display surface.

Description

Technical Field

[0001] The invention belongs to the technical field of display information, and in particular relates to a design structure for electrostatic protection of a broken code display screen. Background Art

[0002] As a widely used display device, the broken code screen is particularly susceptible to static electricity during actual use, resulting in display abnormalities. Especially in the current replacement of new energy vehicles, the larger-sized broken code LCD screen is a cost-effective display device, which is half or more cheaper than the full LCD screen, and is gradually sought after by various instrument manufacturers. However, the non-standard static protection of the broken code ITO design can easily cause static electricity accumulation, especially in the area where the ITO layout has dense wiring and the distance between the wiring is very small. The non-standard design of the shielding line and the ITO wiring can easily lead to abnormal phenomena such as large-area whitening; therefore, many manufacturers are particularly cautious in designing large sizes.

[0003] The general design on the market is to design the shielding loop with a sharp tip in the liquid crystal box, and release the static charge into the air through the tip discharge; or design triangle blocks at the four corners of the ITO glass, and release the pointed triangles on the shielding loop to the triangle blocks at the four corners, and then release them into the air. The blank area between the COM-ITO wiring layer and the SE-ITO wiring layer in the liquid crystal box is designed to fill the triangle blocks or squares, but even so, it cannot solve the existence of the self-built induced electric field in the liquid crystal box, resulting in the continuous accumulation of carriers. Therefore, it is impossible to completely solve the whitening phenomenon caused by the accumulation of static charges in dense display areas.

[0004] Currently, there is a liquid crystal display technology on the market that makes the upper ITO glass into a double-sided ITO mold, coats the upper surface of the upper ITO glass with an ITO conductive film, and uses the entire ITO surface for shielding. However, the discharge path design of the entire conductive film is directly grounded, which not only cannot solve the problem of static electricity accumulation, but also causes EMC test NG, posing serious quality problems.

[0005] It should be noted that the information disclosed in the background technology section of the present invention is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a protective structure that can quickly discharge static electricity and suppress static electricity accumulation. It can not only solve electrostatic interference and avoid the influence of static electricity on the displayed pattern information, but also solve the screen noise phenomenon caused by charge accumulation formed by the movement of carriers in the liquid crystal glass.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A design structure for electrostatic protection of a broken code display screen includes an upper ITO glass, a lower ITO glass, an ITO conductive film, an ITO anti-static shielding loop, an FPC cable, a discharge TVS tube, a silver paste dot and a conductive Mylar. The upper ITO glass is a double-sided conductive ITO glass, the upper surface of the upper ITO glass is designed with a common electrode COM-ITO pen segment routing, the surface of the lower ITO glass is designed with a SEG-ITO routing corresponding to the pen segment of the working pattern, the lower surface of the upper ITO glass has a one-to-one correspondence with the pattern of the upper surface of the lower ITO glass, the surface of the lower ITO glass is an ITO pattern routing, and a layer of the ITO conductive film is adhered to the upper surface of the upper ITO glass.

[0009] On the basis of the above technical solution, the inner surface of the upper ITO glass is the COM electrode of the film wiring, and the corresponding lower ITO glass is a single-sided ITO glass, and the upper surface is the SEG electrode of the film wiring.

[0010] On the basis of the above technical solution, a film shielding trace is provided on the edge of the lower surface of the upper ITO glass, which is a discharge trace. The discharge trace is distributed around the edge of the ITO glass to form a "U"-shaped loop. The discharge trace overlaps with the shielding grounding trace corresponding to the lower ITO glass. The discharge trace is also on the upper surface of the lower ITO glass. It is also distributed on the edge of the ITO glass, away from the film trace of the SEG-ITO and maintains a certain film trace distance from the COM-ITO trace.

[0011] On the basis of the above technical solution, the discharge TVS tube is a TVS tube with transient discharge function.

[0012] On the basis of the above technical solution, the FPC cable (110) is bonded to the lower ITO glass (105) by a Bonging process, and a transmission path for static discharge is distributed in the gold finger pin distribution of the FPC, namely, on the first gold finger and the last gold finger.

[0013] Based on the above technical solution, the ITO conductive film at the lower left and right corners of the upper ITO glass is short-circuited with the shielding traces by applying silver paste and pasted with conductive Mylar, the thickness of which is 0.1 mm.

[0014] Based on the above technical solution, the screen display size is 10.25 inches, and the size of the ITO conductive film can be changed according to design requirements.

[0015] On the basis of the above technical solution, the screen display size is 10.25 inches, and other relatively larger sizes are commonly used. The size of the ITO conductive film is changed according to design requirements.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Suppress EMC radiation and improve the equipment's ability to resist radiation and electrostatic interference;

[0018] 2. Solved the problem that the bias voltage caused by static electricity accumulation caused the liquid crystal molecules to deflect, causing the abnormal phenomenon of whitening of the non-working display segment;

[0019] 3. Solved the problem of display pattern disorder caused by electrostatic discharge;

[0020] 4. Solved the problem of screen distortion caused by film peeling and film pasting;

[0021] 5. The process design and production technology are mature, there are no technical barriers to implementation, and it is easy to operate and can be realized in mass production.

[0022] The additional technical features and advantages of the present invention will be more clearly explained in the following description, or can be understood through the specific practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0024] Figure 1 It is a schematic diagram of the technical structure of the present invention.

[0025] Figure 2 It is a schematic diagram of the internal structure of the broken code screen of the present invention.

[0026] Figure 3 It is the bias level of the working display pattern electrode when the present invention works normally.

[0027] Figure 4 It is the working level of the shielding grounding of the shielding loop line when the present invention is powered on.

[0028] The following are the descriptions of the reference numerals:

[0029] 100. Electrostatic adsorption film; 101. Upper ITO glass; 102. Electrode pen segment; 103. ITO anti-static shielding loop; 104. Driver chip; 105. Lower ITO glass; 106. Conductive Mylar; 107. Polarized glass; 108. ITO conductive film; 109. TVS discharge tube; 110. FPC cable; 112. PCBA motherboard; 113. Liquid crystal molecule LC. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Example

[0032] See also Figure 1-Figure 4 The present invention provides a design structure for electrostatic protection of a broken code display screen: comprising an anti-static adsorption film 100, a polarized glass 107, an upper ITO glass 101, a lower ITO glass 105, a top surface of the upper ITO glass covered with a whole ITO conductive film 108, an ITO anti-static shielding loop 103 designed on the lower surface edge of the upper ITO glass, and a liquid crystal molecule LC 113, the inner film wiring of the upper and lower ITO glasses corresponds to the working display electrode segment 102, the working electrode wiring is divided into SEG-electrode distributed on the lower ITO glass, and COM-ITO electrode distributed on the lower surface of the upper ITO glass, the SEG and COM electrode wiring are output by the driver chip 104, the top surface edge of the lower ITO glass is designed with an ITO anti-static shielding loop 103, the conductive film on the upper ITO glass is short-circuited by dripping silver paste at the bottom of the left and right lower corners of the upper and lower ITO glasses and reinforced by black conductive Mylar 106; the ITO anti-static shielding loop 103 is connected to the PCBA mainboard 112 through the FPC cable 110, and then connected to the main ground through the TVS discharge tube 109 in series.

[0033] Based on the above embodiment: In the case of needing to display rich information patterns, the number of electrode SEG* pen tips controlled by one IC is limited. In order to achieve richer working display patterns, more driver ICs are needed to control, such as Figure 1 As shown, the two driver ICs provided in this solution output more SEG and COM control lines to drive more and richer working display information.

[0034] The driver IC model selected in the design is SC5037, 1 / 1Duty, bias voltage is 1 / 2, driving voltage is 5V, driving frequency is 130hz, and refresh frequency is 60Hz. In order to improve the bias driving capability, COM1, COM2, COM3, and COM4 are short-circuited together, and the VCC supply voltage of the driver IC is 3.3V. The electrodes of the working display segments of the broken code LCD can only be added with AC voltage. The driver IC has a built-in driving circuit that will output the working display segments corresponding to control COM and SEG.

[0035] During normal operation, COM* and SEG* output alternating levels with a fixed period, that is, COM is V+ or 0V, SEG is V- and 0V, and the electrode SEG is the same as COM.

[0036] In any working cycle, the bias voltage of the unselected SEG and COM electrodes is 0V, no self-built electric field is formed, the LC corresponding to the ITO electrode does not deflect, and no backlight penetrates and no working pattern is displayed.

[0037] When the COM and SEG voltages are in different directions, the alternating voltage of the selected working electrode is 2V, and the upper and lower ITO glasses are similar to capacitor plates, and the upper and lower plates form a self-built electric field. After the corresponding electrode is selected, the self-built electric field formed by the constant voltage difference guides the liquid crystal molecules LC 113 to deflect in a directional manner, and the displayed working pattern can be seen after the backlight penetrates.

[0038] When the adsorption film is removed, Figure 2 After the electrostatic adsorption film 100 and the protective film and the polarizer are separated, the adsorption film and the polarizer are charged with different charges. The electrostatic charge on the polarizer can be quickly transferred and released to the PCBA through the conductive film on the ITO. There will be no voltage difference between the electrodes of the upper and lower ITO glasses, and the liquid crystal molecules will not rotate, thus avoiding the electrostatic influence caused by film tearing.

[0039] When static electricity is discharged on the adsorption film, the situation is the same as that on the ITO surface, the static electricity on the upper surface will be quickly released; although the upper and lower ITO glasses are fixed by frame glue, there will be a certain amount of residual charge released into the liquid crystal box, but ITO anti-static shielding loops are designed on the upper and lower edges of the ITO liquid crystal box; at the same time, when designing the module, a stainless steel frame or black conductive cloth tape with shielding and anti-static properties is used to wrap around the sides of the upper and lower ITO glasses to solve the problem of static electricity charge infiltration on the sides. These are all common practices for anti-static protection on the outside of LCD modules in the industry.

[0040] The electrostatic shielding loop has ITO traces on both the COM layer and the SEG layer. The film wiring width of the shielding loop is 0.3mm or more, the distance from the SEG layer electrode is 0.5mm or more, and the distance from the COM layer trace is 0.1mm. This distance is limited by the distribution of the display electrodes on the ITO layer and is related to the wiring of the corresponding electrode SEG and COM traces. Sufficient spacing needs to be retained during design optimization. The electrostatic shielding loop is affected by the coupling of the COM alternating level. The COM trace has a strong driving capability, and the same level will exist on the electrostatic shielding loop.

[0041] When more external charges or carriers accumulate in the liquid crystal box, especially in the area where the SEG electrode layer is wired but the COM electrode layer has no wiring, the SEG electrode accumulates a certain amount of charge and there is a bias relative to the COM layer. As the DC voltage attracts the continuous accumulation of carriers in the box for a long time, a local bias is formed, and the induced internal electric field causes the liquid crystal molecules LC in the corresponding area to deflect, resulting in a whitening or screen distortion phenomenon without an actual working pattern.

[0042] When the upper ITO glass 101 uses a whole piece of ITO film, the ground is connected to the main ground of the PCBA mainboard 112 through a bidirectional TVS tube 109. The COM layer routing is very close, with a distance of 0.1mm. The distributed capacitance and coupling effect make the screen closed loop shielding ground have the same level with the same period. The shielding grounding loop is connected with the upper ITO conductive film 108, that is, there is a certain bias. Even if the SEG layer routing corresponds to the COM layer without routing electrode, the SEG electrode routing and the ITO routing bias at the COM layer without electrode position are just opposite in direction. The bias between the two electrode plates relative to the ITO conductive film 108 layer is basically offset, and a constant induced electric field cannot be formed, that is, the liquid crystal molecules will not be deflected, and there will be no whitening of the screen due to charge accumulation.

[0043] There will be a large number of electrode wirings at the lead-out position of the SEG layer driver chip. There is no wiring in the corresponding COM layer. If the electric field is not offset by the upper ITO film and the SEG layer, the electrodes of this part of the non-working pattern will appear white.

[0044] The model of the bidirectional discharge TVS tube 109 is SMDA05CCN, and its reverse working VRWM voltage is 5V, and the minimum breakdown voltage VBR is 6V. That is, when there is film tearing or electrostatic contact discharge, when the voltage on the loop line exceeds the breakdown voltage VBR-6V, the TVS tube will operate, conduct to the ground to form a discharge path, and release the static electricity.

[0045] The working principle and use process of the present invention are as follows: by applying an upper ITO glass and a layer of antistatic ITO film, the four corners of the ITO film are short-circuited through a ring-shaped electrostatic shielding line with the lower ITO glass 105, the electrostatic shielding line is connected to the PCBA mainboard 112 end through the FPC cable 110, and is discharged to the main ground with the lowest system potential through the TVS discharge tube 109; the shielding ground is used to maintain a synchronous signal with the driving line on the surface, there is no phase difference, the working display pattern has no potential difference, the electric field cannot be self-built, the liquid crystal molecules cannot be deflected, there will be no light transmission, and there will be no abnormal phenomena such as whitening; because the entire ITO film is conductive, when static electricity is generated on the ITO film, the static electricity charge can be quickly drained, and there will be no residual charge on the display surface.

[0046] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A design structure for electrostatic protection of a broken code display screen, comprising an upper ITO glass (101), a lower ITO glass (105), an ITO conductive film (108), an ITO anti-static shielding loop (103), an FPC cable (110), a discharge TVS tube (109), silver paste dots and conductive Mylar (106), characterized in that: The upper ITO glass (101) is a double-sided conductive ITO glass; the upper surface of the upper ITO glass (101) is designed with a common electrode COM-ITO segment routing; the surface of the lower ITO glass (105) is designed with a SEG-ITO routing corresponding to the working pattern segment; the pattern of the lower surface of the upper ITO glass (101) and the upper surface of the lower ITO glass (105) are in one-to-one correspondence; the surface of the lower ITO glass (105) is an ITO pattern routing; and a layer of the ITO conductive film (108) is adhered to the upper surface of the upper ITO glass (101).

2. The design structure of electrostatic protection for a broken code display screen according to claim 1 is characterized in that: The inner surface of the upper ITO glass (101) is a COM electrode for film wiring, and the corresponding lower ITO glass (105) is a single-sided ITO glass, and the upper surface is a SEG electrode for film wiring.

3. The design structure of electrostatic protection for a broken code display screen according to claim 1 is characterized in that: The lower surface edge of the upper ITO glass (101) is provided with a film shielding trace, which is a discharge trace. The discharge trace is distributed around the edge of the ITO glass to form a "U"-shaped loop. The discharge trace overlaps with the shielding ground trace corresponding to the lower ITO glass (105). The discharge trace is also on the upper surface of the lower ITO glass (105). It is also distributed at the edge of the ITO glass and is away from the film trace of the SEG-ITO and maintains a certain film trace distance from the COM-ITO trace.

4. The design structure of electrostatic protection for a broken code display screen according to claim 1 is characterized in that: The FPC cable (110) is bonded to the lower ITO glass (105) by a Bonging process, and a transmission path for static discharge is distributed in the gold finger pin distribution of the FPC, namely, on the first gold finger and the last gold finger.

5. The design structure of electrostatic protection for a broken code display screen according to claim 1 is characterized in that: The discharge TVS tube (109) is a TVS tube with a transient discharge function.

6. The design structure of electrostatic protection for a broken code display screen according to claim 1, characterized in that: The ITO conductive film (108) at the lower left and right corners of the upper ITO glass (101) and the lower ITO glass (105) are short-circuited with a shielding line by applying silver paste, and conductive Mylar is pasted thereon, wherein the thickness of the conductive Mylar is 0.1 mm.

7. The design structure of electrostatic protection for a broken code display screen according to claim 1, characterized in that: The screen display size is 10.25 inches, and the size of the ITO conductive film (108) can be changed according to design requirements.

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